My phpBB 3.2 forum (recently upgraded from 3.1) RSS link http://www.commodore.ca/forum/feed.php results in "No input file specified." and my RSS WordPress Widget shows "RSS Error: A feed could not be found at http://www.commodore.ca/forum/feed.php. A feed with an invalid mime type may fall victim to this error, or SimplePie was unable to auto-discover it.. Use force_feed() if you are certain this URL is a real feed."

I read a number of other forums discussing similar issues when one of the posts includes quotation mark, but I have not seen that.

<IfModule mod_rewrite.c>
RewriteEngine on
#
# Uncomment the statement below if URL rewriting doesn't
# work properly. If you installed phpBB in a subdirectory
# of your site, properly set the argument for the statement.
# e.g.: if your domain is test.com and you installed phpBB
# in http://www.test.com/phpBB/index.php you have to set
# the statement RewriteBase /phpBB/
#
#RewriteBase /
#
# Uncomment the statement below if you want to make use of
# HTTP authentication and it does not already work.
# This could be required if you are for example using PHP via Apache CGI.
#
#RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization},L]
#
# The following 3 lines will rewrite URLs passed through the front controller
# to not require app.php in the actual URL. In other words, a controller is
# by default accessed at /app.php/my/controller, but can also be accessed at
# /my/controller
#
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ app.php [QSA,L]
#
# If symbolic links are not already being followed,
# uncomment the line below.
# http://anothersysadmin.wordpress.com/2008/06/10/mod_rewrite-forbidden-403-with-apache-228/
#
#Options +FollowSymLinks
</IfModule>
# With Apache 2.4 the "Order, Deny" syntax has been deprecated and moved from
# module mod_authz_host to a new module called mod_access_compat (which may be
# disabled) and a new "Require" syntax has been introduced to mod_authz_host.
# We could just conditionally provide both versions, but unfortunately Apache
# does not explicitly tell us its version if the module mod_version is not
# available. In this case, we check for the availability of module
# mod_authz_core (which should be on 2.4 or higher only) as a best guess.
<IfModule mod_version.c>
<IfVersion < 2.4>
<Files "config.php">
Order Allow,Deny
Deny from All
</Files>
<Files "common.php">
Order Allow,Deny
Deny from All
</Files>
</IfVersion>
<IfVersion >= 2.4>
<Files "config.php">
Require all denied
</Files>
<Files "common.php">
Require all denied
</Files>
</IfVersion>
</IfModule>
<IfModule !mod_version.c>
<IfModule !mod_authz_core.c>
<Files "config.php">
Order Allow,Deny
Deny from All
</Files>
<Files "common.php">
Order Allow,Deny
Deny from All
</Files>
</IfModule>
<IfModule mod_authz_core.c>
<Files "config.php">
Require all denied
</Files>
<Files "common.php">
Require all denied
</Files>
</IfModule>
</IfModule>

I did not have a PHP.INI so I called GoDaddy and confirmed I should just create one. I put a php.ini in the root and have cgi.fix_pathinfo=1 as the only entry in it. Then I ended all of the running tasks on my GoDaddy hosting account, and refreshed https://www.commodore.ca/forum/app.php/feed but found the same error.